File System Operations

import { 
  readFile, readFileSync,
  writeFile, writeFileSync,
  mkdir, mkdirSync,
  unlink, unlinkSync,
  stat, statSync,
  exists, existsSync,
  readdir, readdirSync
} from 'ant:fs';

// Read as Buffer (Uint8Array)
const data = await readFile('data.bin');

// Read as UTF-8 string
const text = await readFile('file.txt', 'utf8');

// Read with encoding options
const content = await readFile('file.txt', { encoding: 'utf8' });

const data = readFileSync('config.json', 'utf8');
const json = JSON.parse(data);

// Read as base64
const encoded = await readFile('image.png', 'base64');

// Read as hex
const hex = await readFile('data.bin', 'hex');

// Write string
await writeFile('output.txt', 'Hello, World!');

// Write JSON
await writeFile('data.json', JSON.stringify({ key: 'value' }));

// Write with encoding
await writeFile('file.txt', data, 'utf8');

writeFileSync('log.txt', 'Log entry\n');
writeFileSync('config.json', JSON.stringify(config, null, 2));

// Sync append
appendFileSync('log.txt', 'New log entry\n');
appendFileSync('data.csv', 'row1,row2,row3\n');

const stats = await stat('file.txt');
console.log(stats.size);      // File size in bytes
console.log(stats.mode);      // File permissions
console.log(stats.uid);       // User ID
console.log(stats.gid);       // Group ID

// Check file type
if (stats.isFile()) {
  console.log('It\'s a file');
}
if (stats.isDirectory()) {
  console.log('It\'s a directory');
}
if (stats.isSymbolicLink()) {
  console.log('It\'s a symlink');
}

const stats = statSync('package.json');
if (stats.isFile()) {
  console.log(`File size: ${stats.size} bytes`);
}

if (await exists('config.json')) {
  console.log('File exists');
}

if (existsSync('data.txt')) {
  const data = readFileSync('data.txt', 'utf8');
}

// Async create
await mkdir('new-dir');

// Create with permissions
await mkdir('secure-dir', 0o755);

// Create with options (recursive)
await mkdir('path/to/nested/dir', { recursive: true });

// Sync create
mkdirSync('output');
mkdirSync('nested/path', { recursive: true });

// Async remove
await rmdir('old-dir');

// Sync remove
rmdirSync('temp');

// Async list
const files = await readdir('.');
for (const file of files) {
  console.log(file);
}

// Sync list
const entries = readdirSync('/tmp');
console.log(entries);

// Async delete
await unlink('old-file.txt');

// Sync delete
unlinkSync('temp.log');

copyFileSync('source.txt', 'destination.txt');

renameSync('old-name.txt', 'new-name.txt');
renameSync('file.txt', 'other-dir/file.txt'); // Move to another directory

import { constants } from 'ant:fs';

// Check if file is readable
try {
  await access('file.txt', constants.R_OK);
  console.log('File is readable');
} catch (err) {
  console.log('File is not readable');
}

// Sync access check
try {
  accessSync('file.txt', constants.W_OK);
  console.log('File is writable');
} catch (err) {
  console.log('File is not writable');
}

import { open, read, write, close, openSync, readSync, writeSync, closeSync } from 'ant:fs';

// Async file descriptor operations
const fd = await open('file.txt', 'r');
const buffer = new Uint8Array(1024);
const bytesRead = await read(fd, buffer);
await close(fd);

// Sync file descriptor operations
const fd2 = openSync('output.bin', 'w');
const data = new Uint8Array([1, 2, 3, 4]);
const bytesWritten = writeSync(fd2, data);
closeSync(fd2);

const fd = await open('large-file.bin', 'r');
const buffer = new Uint8Array(512);

// Read 256 bytes starting at position 1024
const bytesRead = await read(fd, buffer, {
  offset: 0,      // Buffer offset
  length: 256,    // Bytes to read
  position: 1024  // File position
});

await close(fd);

const fd = await open('file.bin', 'w');
const data = new Uint8Array([10, 20, 30, 40, 50]);

// Write 3 bytes starting from buffer offset 1 at file position 0
const bytesWritten = await write(fd, data, {
  offset: 1,    // Buffer offset
  length: 3,    // Bytes to write
  position: 0   // File position
});

await close(fd);

try {
  const data = await readFile('missing.txt');
} catch (err) {
  console.error('Error reading file:', err.message);
  console.error('Error code:', err.code); // ENOENT, EACCES, etc.
}

// Sync error handling
try {
  writeFileSync('/readonly/file.txt', 'data');
} catch (err) {
  if (err.code === 'EACCES') {
    console.error('Permission denied');
  }
}

import { join, dirname, basename } from 'ant:path';
import { readFile } from 'ant:fs';

const configPath = join(import.meta.dirname, 'config.json');
const config = await readFile(configPath, 'utf8');

const dir = dirname('/path/to/file.txt');   // '/path/to'
const name = basename('/path/to/file.txt'); // 'file.txt'